A111687 Comprimorial(n): the product of the first n primes and the first n composite numbers.

8, 144, 5760, 362880, 39916800, 6227020800, 1482030950400, 422378820864000, 155435406077952000, 81137281972690944000, 50305114823068385280000, 39087074217524135362560000, 35256540944206770097029120000

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..215

Formula

a(n) = A002110(n)*A036691(n) for n>=1. - Rick L. Shepherd, Aug 20 2005

Example

a(1) = 2*4 = 8, a(2) = (2*3)*(4*6)=144.

Mathematica

Module[{nn=50, prs, coms, len}, prs=Select[Range[nn], PrimeQ]; coms=Complement[ Range[4, nn], prs]; len=Min[Length[prs], Length[coms]]; Rest[FoldList[ Times, 1, Times@@@Thread[{Take[prs, len], Take[coms, len]}]]]] (* Harvey P. Dale, Jan 11 2014 *)

Crossrefs

Cf. A002110 (primorials), A036691 (compositorials).

Sequence in context: A341957 A024284 A024285 * A231851 A071305 A172150

Adjacent sequences: A111684 A111685 A111686 * A111688 A111689 A111690

Keyword

nonn

Author

Amarnath Murthy, Aug 17 2005

Extensions

Corrected and extended by Rick L. Shepherd, Aug 20 2005

Status

approved